Linear polymers containing regularly recurring ester and amide linkages



United States Patent LINEAR POLYMERS CONTAINING This invention relatesto new linear, amideandestercontaining polymers. In particular, thisinvention relates to polymers characterized by regularity of recurrenceof" the ester and amide linkages inthe unit repeating chain.

These compositions are more fully characterized bythe formula,

i lQ R QQ QNHR"1ANHQQR"'Q13 in which x is the number of repeating unitsand is of such magnitude as to give rise to, high molecular weightpolymer (of a reduced viscosity of at least 0.4); n is-'s'elecitfid;from the group consisting ofCt-and lywhenn 'is Patented July 26 19 60ice point of view that an arrangement permitting maximum conjunction ofinteracting groups between neighboring molecules'leads tomaximuminteraction and, thus, the greatest possibleintermolecular'attraction. On the other hand, a random arrangement ofthe interacting groups in the chain permits only a fraction of thegroups to be" in juxtaposition and results in a weakening ofintermolecular attraction over'that obtainable by a regular arrayTherefore, although such mixtures of. reactants as those containingacid, hydroxyl and amine groups produce polymers containing both amideand ester links, the. random placement of these groups leads to polymersof little value for fibers, I 7

We have now succeeded in producing a class of fiberforming polymerscharacterized by a regularly recurrent series of amide and ester groupsin a predetermined structurei iwee e c stituent tsh h at n Structure areselected and fbuilt into the reactantsfform- 1,, R'- equals R and, ingeneral, 11', R" and R-' are divalent hydrocarbon radicals free. fromolefinic andnacet ylenic unsaturation, and R isthe divalent residue ofan or a ic dicar oxylic a id, the residue b i di e hydrocarbon chainfree from olefinic and acetylenic un'-: satura o n which maycqntain, "asamember of the chain, an ether'or thioether link.

Polymeric, compositions containing both ,ester' and idelinkages are:known to the art; however, to our knowledge, a polymer-containingaregularly repeating structure of; amide and ester linkages, as depicted,'is new.

Previous attempts at producingfa'polymer'containing- I ester andamide'linlcages havemot'producefd polyr'nersiof any. particular worth asTfiber and filament" formers. 'An answer to whythese results shouldhesois found in the currently ajcceptediexplanations of themglculanproprties giving rise to good fiber and filament-"fonning 'pblymers. Such explanations are-not all-enveloping and are ty 0 an acid toreact in the reactantsfnainly n with facility with botliarnineandhydroxyl groups, a

ans qrn ar an ement 9f este and anidel n ss is Produced rather than aregularly repeating s tru eture,. y lnasmuch as te s e s n th a de rabprope tyin-filamentsand fibers is clo l a$s99ie d with"mstallinitnwhihrm i m de n en upon the n kingprbpert 9t the nt r o e ular f rces beween he. pnlvmer molecules; regularity of structure is a highlydje'sirableproperty in a fibenformifig POM/ 1 1; This come about;because iall portions of the polymeric chains are not equally Wellendowed with the propertiesfde'pendent uponthe atomic structures of thechain constituents,"that=give rise'tii the intermolecular forcesholdinginolecules togetherand the geometrical configurationsthat-permitclose'packing. i'he spatial arrangement of theatomic'constitueirts" givingrise; intemolewlar F r e mitate??? he-a s V.

ing the polymers. In our new polymers the ester links arise in thepolymerization reaction; the amide, links are introduced by'way of a newclass 'o'f diols described below. Reacting a member of this class ofdiols with a dicarboxylic acid results in thepolymers of this invention.

In general, diols useful in the practiceof this invention have thestructure, i i

HOR' [CONHR"] NHCOR "OH in which n is selected from the group consistingof 0' and 1'.' When n is 0, R' is a divalent saturated hydrocarbon chainof at 'least four carbon atoms' in length and R is a divalenthydrocarbon chain free from. olefinic and acetylenic unsaturation of atleast twocarbon atoms in length. When n is 1,R equals R'- and Rand R'are saturated divalent hydrocarbonchains of'atfleast four carbon atomsin length, and R" is a divalent hydrocarbon chain free from olefinic'andacetylenicunsaturation of at least two carbon atoms in length. Thepreferred diols are derived, the case monoamide diols (n=0 in theformula), from'the reaction of an omega hydroxy primary amine and anomega lactone, and, the

, diamide diols (n=. l in the formula) from a diprimary diamine and anomega lactone. Ihe preferred omega in which'A is a saturated divalenthydrocarbon chain of at least four carbon atoms in'length and whichappears as 1K? in the "amide :di ol sf and .ias R's and R 5: "in thediamide diols. The radicals, R', when equals zero, and

R andRfi', when n' equals one, should nerbe "shorter than four carbonatomsfinlengthf with sherter radical lengths, and under the strenuousconditions of heat and reduced pressure necessaryinpolyesterilieatiqnreactions,

the diols are no longerstable. For example',when polymeriiation" of N, Ndi(4 hydroxybutyryl)hexamethylenediamine (R and R'" equal a chain lengthof three carbon atoms) with-'adipic "acid in the p ese eepraddedbutyi'olactorie, wasattein tem'anampunt er lactone was" recovered thatindicated -that '86 per'cent of the lactone contained inthe 'diamidediol charged had revertedjto free-'brityrolactone. On the' othen hand,the behavior diols derived from delta-valerolactone'is quite'diiferent,-'

a small amountbf the free vale rolactone added to' the reaction mixturerepresses the l tendency to form delta- 3 valerolactone fromthediqlsY'Cons'equently (n61; when equaltd, or greater than four earn-5nremsj hm zero, and witli R andiR equal'tojor' gr titliafrfb r' Suitableomega hydroxy primary amines and diprimary diamines for the formation ofthe diols are those in which the functional groups are joined by adivalent hydrocarbon chain free from olefinic and acetylenicunsaturation in which the'minimum chain length is at least two carbonatoms. In thediols formula this divalent chain appears as R in themonoamide diols, and R" in the diamide diols. I

Inasmuch as the number of suitable diols, answering to the previousdescription, isfar too vast for complete and individual listing, only afew of the class, and these only by way of illustrating in a verygeneral way the possible structural modifications, are herein listed:

Amide diols (11:0):

N, hydroxyethyl, 6-hydroxy caproamide HO(CH NHCO(CH OHN,3-hydroxypropyl,S-hydroxyvaleramide HO(CH NHCO(CH OH vN,4-hydroxybutyl,5-hydroxy,3- methylvaleramide HO (CH NHCOCH CH(CH CH CHOH N,8-hydroxyoctyl,IO-hydroxydecanoaniide HO( CH NI-ICO (CH HN,10-hydroxydecyl,S-hydroxyvaleramide HO(CH NHCO(CH OHN-p-hydroxyxylyl,6-hydroxycaproamide HOCH 0CH NHCO(CH OH These monamidediols are but 6 of the 24 possible diols; obtainable using only thoseomega hydroxy primary amines and omega lactones from which the aboveexamples were derived. Diamide diols (rt-=1): v

N,N' di 5 -hydroxyvaleryl) ethylenediamine HO (CH ,CONH CH NHCO CH 0HN,Ndi(5-hydroxy,3-methylvaleryl) hexa methylenediamine I-IOCH CH CH( CHCH CONH(CH 5 NHCOCH CH(CH )CH CH OH N,Ndi( 6-hydroxycaproyl)octamethylenediamine HO(CH CONH(CH NHCO(CH OI-I N,Ndi( S-hydroxyvaleryl)decamethylenediamine HO (CH CONHQCH NHCO(CH OH N,N'di(5-hydroxyvaleryl)p-phenylenediamine N,N'di( 10-hydroxydecanoyl)p,p'bi-phenylenediamine N,N'di(6-hydroxycaproy1)2-6 naphthalenediamineno omnoonn V NHOO 011. .011

I acetylenic unsaturation, but including divalent chains such as thosewhich contain an ether link, and'divalent chains which, contain athioether link Illustrative of dicarboxylic acids containing an inert,divalent organic radical are alkylene diacids such as' succinic, adipicand sebacic acids, arylene diacids such as terephthalic,p,p'-diphenyldicarboxylic, and p,p'dipheny1methane dicarboxylic acids,and ether and thioether diacids such as di( 3 carboxy- 4 ethyl) etherand di(fi-carboxyethyl) thioether. This inert, divalent organic radical,R, is at least two carbon atoms in length.

[CORCOOR ECONHR" N IICOR"O] x V in which x is the number of repeatingunits, n is 0 and 1,

i when n is 0, R' is a saturated divalent hydrocarbon chain of at leastfour carbon atoms, and, when n is 1, R and R' are saturated divalenthydrocarbon chains of at least four carbon atoms, R" is a divalenthydrocarbon chain free from olefinic and acetylenic unsaturation and atleast two carbon atoms in length, R is an inert divalent organicradical, as previously defined, of at least two carbon atoms in length.I

These polymers are produced in a two-stage process. In the first stagethe diol and diacid are reacted in an oxygen-free nitrogen atmosphere ata temperature of 100 C. to 300 C., and at atmospheric pressure; in thesecond stage the heating is maintained and the pressure is reduced to lto 3 mm. of Hg, or less, thus completing the polymerization. A catalystsuch as heptafluorobutyric acid may be used but is not a necessity.Small amounts of the omega lactone used in the synthesis of the diolreactant may be added to repress the breakdown of the amide links of thediols. Such lactone does not react in the polymerization process and isadded in the initial stage and removed in the second stage of heatingunder vacuum. l a 7 Our polymers, containing ester and amide groups in aregularly recurrent unit structure, form filaments, fibers and films;they may be cast into flexible rods, and they may be melt spuna Thepolymers formed in accordance with this invention may be varied inproperties, by proper choice of hydrocarbon chain constituents, thuscontrolling the juxtaposition of interacting groups in neighboringmolecules, and the chain rigidity associated with arylene radicals asopposed to the more flexible alkylene radicals, from tough and flexibleto rubbery and elastic solids.

The following examples serve to illustrate the practice of thisinvention.

" ExampleI' Terephthalic acid (0.226 mol) andN,Ndi(6-hydroxycaproyl)hexamethylenediamine (0.232 mol) along withheptafluoro butyric acid, 2 percent of the charge, as 'a catalyst, werereacted in an oxygen-free nitrogen atmosphere for 19 hours at 260 C. atatmospheric pressure and for 9 hours at 260 C. at 1 mm. of Hg. Theresultant polymer melted at 230 C. and had a reduced viscosity of 0.5 inm-cresol. 1-?ibers were produced from a melt, that were capable'of beingcold drawn. The poly-Q mer was tough and couldbe cast into flexiblerods.

Example 11 This example shows that the condensation 'is not 'dependentupon a catalyst.

Terephthalic acid (0.226'mol) andN,N'di(6-hydroxycaproyl)hexamethylenediamine (0.232 mol)]we re reactedin an oxygen-free nitrogen atmosphere for 22 hours at, 260 C. atatmospheric pressure and for 5.5 hours at 260 C. at 1 mm. of Hg withoutuse of acatalyst. fibers 7 could be pulled from a melt of the polymer. 7

Example III 225 C. at 3 mm. of Hg. A tough polymer with a melting pointof 133 C. and a reduced viscosity of 0.4 was obtained. The polymer wasfurther heated in a molecular still for 19 hours at 200 C. at less than1 mm. of Hg and then had a reduced viscosity of 0.94, and a meltingpoint of 140 C. From the molten state the polymer was cast into a rod /2inch in diameter, and then extruded through a single orifice 0.014 inchin diameter. The filaments so produced could be cold drawn 470 percent,and after cold drawing had a tenacity of 1.7 grams per denier, with anultimate elongation of 523 percent, and a modulus of elasticity of 3.2grams per denier.

Example IV Adipic acid (0.192 mol) and N, N di(6-hydroxycaproyl)ethylenediamine (0.200 mol) along with 2 percent of the charge ofheptafiuorobutyric acid as catalyst were reacted in a nitrogenatmosphere at 110 C. to 120 C. for 24 hours at 1 atmospheric pressureand for 9 hours at 200 C. at 1 mm. of Hg. The resultant polymer producedfibers from a melt.

Example V This example illustrates that small amounts of the lactoneused in the synthesis of the amide-dials may be added without reactingwith the polymerization mixture.

Adipic acid (0.10 mol) and N, N di (S-hydroxyvaleryl)hexamethylenediamine (0.10 mol) were reacted in an oxygen-free nitrogenatmosphere for- 16.5 hours at 200 C. and 760 mm. of Hg with 2 percent ofthe charge of perfluorooctanoic acid added as a catalyst. The reactionwas completed by heating for 5 hours at 200 C. at 1 mm. of Hg. Toprevent breakdown of the diamidediol, delta valerolactone (0.05 mol) wasadded in the initial reaction phase and removed by volatilization in thevacuum heating phase. A'polymer having a light color was obtained whichhad a melting point of 140? C. and a reduced viscosity of 0.46. Whenmolten it could be pulled into filaments which would easily cold draw.The theoretical nitrogen content of this polymer for the correct numberof amide links is 6.21 percent. Nitrogen analysis of the polymer gave6.31 percent nitrogen indicating no reaction of the excessvalerolactone.

Example Vl This example shows the use of a monoamide diol.

Adipic acid (0.30 mol) and N hydroxyethyl, 6-hydroxycaproamide (0.306mol) were reacted in an oxygen free nitrogen atmosphere for 18 hours at100 C., 23 hours at 200 C. at atmospheric pressure and for 5.5 hours at200 C. and 1 mm. of Hg. Two percent of the charge of heptafiuorobutyricacid was used as a catalyst. The resultant polymer was heated furtherfor 42 hours at 225 C. to 250 C. in a molecular still at less than 1 mm.of Hg giving a final product which was distinctly rubbery and elastic atroom temperature and very viscous, at temperatures up to 200 C., in a.melt. The polymer had a reduced viscosity of 0.9. An elastic transparentfilm was obtained from the polymer.

Example VII 7 The polymer had a melting point of 140 C. and a reducedviscosity of 0.90. Filaments could be pulled from a melt and exhibitedgood cold-drawing and elastic properties.

What is claimed is:

1. A fiber-forming, resinous polyester having a reduced viscosity of atleast 0.4 in m-cresol, of (1) an organic dicarboxylic acid representedby the structural formula:

HOOCRCOOH wherein R is a member selected from the bon atoms and (2) anN, N di(omega hydroxy alkyl) acid and the nitrogenatoms of the N, Ndi(omega hydroxy alkyl) diamido-substituted hydrocarbon compound arelinked to each other through a mononuclear arylene radical.

3. The polyester of claim 1, wherein the organic dicarboxylic acid'is amononuclear aromatic dicarboxylic acid and the nitrogen atoms of the N,N di(omega hydroxy alkyl) diamido-substituted hydrocarbon compound arelinked to each other through an alkylene radical chain containing from 2to 10 carbon atoms.

4. The polyester of claim 1, wherein the organic dicarboxylic acid is analkylene dicarboxylic acid in which the alkylene radical is a chaincontaining from 2 to 10 carbon atoms and the nitrogen atoms of the N, Ndi- (omega hydroxy alkyl) diamido-substituted hydrocarbon compoundarelinked to each other through an alkylene radical chain containingfrom 2 to 10 carbon atoms.

5. The process for producing a polymer having the basic structurewherein x is of such magnitude as to give rise to fiberforming polymershaving a reduced viscosity of at least about 0.4 in m-cresol, R equalsR", R and R are saturated divalent hydrocarbon chains of from 4 to 6carbon atoms, and R" is a divalent hydrocarbon chain free from olefinicand acetylenic unsaturation of from 2 to 10 carbon atoms, R is a memberselected from the group consisting of divalent hydrocarbon radicals freefrom olefinic and acetylenic unsaturation and containing from 2 to 12carbon atoms, divalent hydrocarbon ether radicals free from olefinic andacetylenic unsaturation and containing from 2 to 12 carbon atoms, anddivalent hydrocarbon thioether radicals free from olefinic andacetylenic unsaturation and containing from 2 to 12 carbon atoms, whichcomprises reacting a diol of the formula HORCONHR"NHCOR"'OH wherein R,R" and R" are as above defined, with a diacid of the formula HOOCRCOOHwherein R is as above defined, in two steps, the first step comprisingreacting the diol and diacid in an oxygen-free nitrogen atmosphere at atemperature of C. to 300 C. and at atmospheric pressures, the secondstep comprising maintaining the temperature at 100 C. to 300 C. andcompleting the polymerization under pressures less than 3 mm. of Hg.

References Cited in the file of this patent UNITED STATES PATENTS2,551,731 Drewitt et al. May 8, 1951 i FOREIGN PATENTS 64,261 I. G. F.Netherlands Oct. 15, 1949

1. A FIBER-FORMING, RESINOUS POLYESTER HAVING A REDUCED VISCOSITY OF AT LEAST 0.4 IN M-CRESOL, OF (1) AND ORGANIC DICARBOXYLIC ACID REPRESENTED BY THE STRUCTURAL FORMULA: HOOCRCOOH WHEREIN R IS A MEMBER SELECTED FROM THE GROUP CONSISTING OF DIVALENT HYDROCARBON RADICALS FREE FROM OLEFINIC AND ACETYLENIC UNSATURATION AND CONTAINING FROM 2 TO 12 CARBON ATOMS, DIVALENT HYDROCARBON ETHER RADICALS FREE FROM OLEFINIC AND ACETYLENIC UNSATURATION AND CONTAINING FROM 2 TO 12 CARBON ATOMS, AND DIVALENT HYDROCARBON THIOETHER RADICALS FREE FROM OLEFINIC AND ACETYLENIC UNSATURATION AND CONTAINING FROM 2 TO 12 CARBON ATOMS AND (2) AND N, N'' DI(OMEGA HYDROXY ALKYL) DIAMIDO-SUBSTITUTED HYDROCARBON COMPOUND WHEREIN THE OMEGA HYDROXY ALKYL AMIDO RADICALS OF SAID COMPOUND CONTAIN FROM 4 TO 6 CARBON ATOMS AND THE NITROGEN ATOMS OF SAID AMIDO RADICALS ARE LINKED TO EACH OTHER THROUGH A DIVALENT HYDROCARBON RADICAL FREE FROM OLEFINIC AND ACETYLENIC UNSATURATION AND CONTAINING FROM 2 TO 10 CHAIN CARBON ATOMS. 